This invention relates in general to apparatus for filtering and separating liquids and deals more particularly with a fuel conditioning apparatus for removing foreign particles and separating water from fuel in the fuel supply system for an internal combustion engine or the like. The fuel conditioner of the present invention is particularly adapted for connection in the fuel supply system for a diesel engine to remove foreign particles and separate water from fuel before supplying the fuel to the engine.
Increasing demands for diesel fuel have resulted in a marked increase in poorly handled fuel on the market. More water is being found in fuel than ever before. Abrasive particles in diesel fuel can permanently damage precision components in a fuel-injection pump or cause wear which can destroy the ability of the pump to meter or deliver fuel at high pressure. The presence of water in diesel fuel can cause rusting and freezing resulting in the seizure of moving parts and/or clogging of the vital fuel injection system.
Diesel fuel contains a waxy constituent which precipitates as small wax crystals when the fuel temperature drops below its "cloud point". During cold weather operation, these wax crystals can quickly plug a fuel filter and thereby cut-off fuel delivery to an engine. This condition is particularly noticeable with Number 2 diesel fuel, and is expected to become even more prevalent in the future, because of fuel grade modifications.
Fuel conditioners have heretofore been provided for connection in a fuel supply system for removing particulate material and separating water from fuel. In a fuel conditioner of the type which utilizes a throwaway filter element or disposable cartridge, some fuel invariably escapes from associated fuel lines when a contaminated cartridge is removed and replaced by a new one. The usual procedure for restoring an engine to operation after a fuel conditioner cartridge has been replaced is to crank the engine until air has been expelled from the fuel supply system and normal flow of fuel to the engine has been restored. This procedure causes battery drain and unnecessary wear to the starter and other engine parts.
Accordingly, it is the general aim of this invention to provide an improved fuel conditioner which enables more efficient removal of foreign particles and separation of water from fuel. It is a further aim of the invention to provide an improved fuel conditioner of disposable cartridge type which includes means for preventing or at least substantially reducing waxy buildup in the filter media within the disposable cartridge to permit operation at lower temperatures. A still further aim of the invention is to provide an improved fuel conditioner for the fuel supply system of an internal combustion engine and which includes means for restoring the fuel supply system to its normal fuel delivery condition after a disposable cartridge is replaced and without cranking the engine.